Bone Mineral Density at the Hip Predicts Mortality in Elderly Men

Low bone density as assessed by calcaneal ultrasound has been associated with mortality in elderly men and women. We examined the relationship between bone density measured at the hip and all cause and cardiovascular mortality in elderly men. Men aged 65–76 years from the general community were recruited from general practices in Cambridge between 1991 and 1995. At baseline survey, data collection included health questionnaires, measures of anthropometry and cardiovascular risk factors, as well as bone mineral density (BMD) measured using dual energy X-ray absorptiometry. All men have been followed up for vital status up to December 1999. BMD was significantly inversely related to mortality from all causes and cardiovascular disease, with decreasing rates with increasing bone density quartile, and an approximate halving of risk between the bottom and top quartile (p <0.002, test for trend all causes and p <0.025, test for trend for cardiovascular deaths). In multivariate analyses using the Cox proportional hazards model, an increase of 1 standard deviation (0.144 g/cm²) in total hip bone density was significantly associated with an age-adjusted 0.77 relative risk (95% CI 0.66–0.91) for all-cause mortality and 0.76 relative risk (95% CI 0.62–0.93) for cardiovascular disease mortality. The association remained significant after adjusting for age, body mass index, cigarette smoking status, serum cholesterol, systolic blood pressure, past history of heart attack, stroke or cancer and other lifestyle factors which included use of alcohol, physical activity and general health status. Low bone density at the hip is thus a strong and independent predictor of all-cause and cardiovascular mortality in older men. Received: 16 August 2000 / Accepted: 27 October 2000     

慢性肾衰竭患者血浆NT-proBNP水平的研究

目的探讨慢性肾衰竭患者血浆脑钠肽前体N末端片段（N—terminal-pro—brain natriuretic prptide,NT-proBNP）水平与慢性肾功能不全之间的关系。方法选择临床诊断慢性肾衰竭患者59例,根据肾小球滤过率将患者分为氮质血症期25例、肾衰竭期20例、尿毒症期14例,对照组20例。检测血浆NT—proBNP水平、测量超声心动图并收集患者临床资料。对比不同肾功能状态患者的血浆NT—proBNP水平差异及其与肾功能损害等临床指标及心脏结构功能改变之间的相关性。结果慢性肾衰竭各期患者血浆NT-proBNP水平明显升高,且与左心室后壁厚度、血磷水平正相关,与左室射血分数呈负相关。结论慢性肾衰竭患者血浆NT-proBNP水平升高,其浓度与患者心脏结构和功能的改变以及肾功能下降有关。血浆NT-proBNP水平可作为慢性肾衰竭患者心血管疾病的生化指标。     

Hepatitis C inflection in dialysis patients: a link to poor clinical outcome?

Among the 350,000 maintenance dialysis patients in the USA, the mortality rate is high (20–23% per year) as is the prevalence of hepatitis C virus (HCV) infection (5–15%). An additional same number of dialysis patients in the USA may be infected with HCV but have undetectable HCV antibodies. Almost half of all deaths in dialysis patients, including HCV-infected patients, are due to cardiovascular disease. Since over two-thirds of dialysis patients die within 5 years of initiating dialysis and because markers of malnutrition–inflammation complex syndrome (MICS), rather than traditional cardiovascular risk factors, are among the strongest predictors of early death in these patients, the impact of HCV infection on nutritional status and inflammation may be a main cause of poor survival in this population. Based on data from our cross-sectional and limited longitudinal studies, we hypothesize that HCV infection confounds the association between MICS and clinical outcomes in dialysis patients and, by doing so, leads to higher short-term cardiovascular events and death. Understanding the natural history of HCV and its association with inflammation, nutrition and outcomes in dialysis patients may lead to testing more effective anti-HCV management strategies in this and other similar patient populations, providing benefits not only for HCV infection but the detrimental consequences associated with this infection. In this article, we review the link between the HCV infection and mortality in dialysis patients and compare HCV antibody to molecular methods to detect HCV infection in these individuals. Funding source: Supported by a Young Investigator Award from the National Kidney Foundation; the National Institute of Diabetes, Digestive and Kidney Disease grant # DK61162; and a research grant from DaVita (for KKZ); and the National Institute of Allergy and Infectious Diseases grant # AI01831 (for LGM and HD41224 (for ESD)).     

Relationship between insulin resistance and increased carotid artery intima-media thickness in non-diabetic kidney disease patients

Objective To evaluate the relationship of insulin resistance (IR) and carotid artery intima-media thickness (CA-IMT), plaque status in non-diabetic non-dialysis chronic kidney disease (CKD) patients with different stages. Methods One hundred and seventeen non-diabetes non-dialysis CKD patients were enrolled into this cross-sectional observational study. Insulin resistance index (HOME-IR) was assessed by the homeostasis model assessment. Patients with HOME-IR≥1.73 were defined as insulin resistance. And patients with CA-IMT≥0.9 mm were defined as thickening. The blood pressure measurement, heart Doppler ultrasound, bilateral carotid artery ultrasound examination, blood biochemistry and urine protein test were performed, eGFR was calculated by EPI formula. Results The prevalence of IR was 47.01% in 117 non-diabetic non-dialysis CKD patients, and it was 35.71%, 50.00% and 54.55% in eGFR≥60ml•min-1•(1.73 m2)-1 group, 30≤eGFR＜60ml•min-1•(1.73 m2)-1 group, and eGFR＜30ml•min-1•(1.73 m2)-1 group separately. In eGFR＜30ml•min-1•(1.73 m2)-1 group, cystain C, homocysteine, parathyroid hormone, Scr, BUN, uric acid, interventricular septal thickness, left ventricular dimension, left ventricular posterior wall thickness were significantly higher than that in the other two groups (P＜0.01), while the level of hemoglobin was significantly lower (P＜0.01); then the levels of serum albumin and systolic pressure were higher than that in the eGFR≥60ml•min-1•(1.73 m2)-1 group, however, the levels of total cholesterol and low-density lipoprotein-cholesterol were lower than that in the eGFR≥60ml•min-1•(1.73 m2)-1 group. Correlation analysis showed that insulin resistance index was significantly correlated with CA-IMT (r=0.444, P=0.006）in the eGFR＜30ml•min-1•(1.73 m2)-1 group, however, there wasn’t correlation in other two groups. And although insulin resistance wasn’t correlated with soft plaque, it was significantly correlated with hard plaque (χ2=6.476, P=0.011) in the eGFR＜30ml•min-1•(1.73 m2)-1 group. The Logistic regression analysis results displayed aging increase was the independent risk factor of the CA-IMT thickening for non-diabetes non-dialysis CKD patients but not insulin resistance. Conclusions HOMA-IR is correlated with CA-IMT and hard plaque when eGFR＜30ml•min-1•(1.73 m2)-1 in non-diabetes non-dialysis CKD patients. However, the insulin resistance isn’t the independent risk factor of the CA-IMT thickening for non-diabetes non-dialysis CKD patients.     

In Vitro Comparison of Two Different Mechanical Circulatory Support Devices Installed in Series and in Parallel

This study investigates the novel approach of placing a ventricular assist pump in the descending aorta in series configuration with the heart and compares it with the two traditional approaches of left‐ventricle‐to‐ascending‐aorta (LV‐AA) and left‐ventricle‐to‐descending‐aorta (LV‐DA) placement in parallel with the heart. Experiments were conducted by using the in‐house simulator of the cardiovascular blood‐flow loop (SCVL). The results indicate that the use of the LV‐AA in‐parallel configuration leads to a significant improvement in the systemic and pulmonic flow as the level of continuous flow is increased; however, this approach is considered highly invasive. The use of the LV‐DA in‐parallel configuration leads to an improvement in the systemic and pulmonic flow at lower levels of continuous flow but at higher levels of pump support leads to retrograde flow. In both in‐parallel configurations, increasing the level of pump continuous flow leads to a decrease in pulsatility to a certain extent. The results of placing the pump in the descending aorta in series configuration show that the pressure drop upstream of the pump facilitates cardiac output as a result of afterload reduction. In addition, the pressure rise downstream of the pump may assist with renal perfusion. However, at the same time, the pressure drop generated at the proximal part of the descending aorta induces a slight drop in carotid perfusion, which would be autoregulated by the brain in a native cardiovascular system. The pulse wave analysis shows that placing the pump in the descending aorta leads to improved pulsatility in comparison with the traditional in‐parallel configurations.     

缺血修饰白蛋白水平与血液透析患者心血管疾病的相关分析

目的探讨维持性血液透析（maintenance hemodialysis,MHD）患者缺血修饰白蛋白（ischemia modified albumin,IMA）水平的变化及其与心血管疾病（cardiovasculardisease,CVD）的关系。方法回顾性分析86例MHD患者的临床及实验室结果。根据患者是否发生CVD分为CVD组和非CVD组,分析2组患者的临床特点和实验室检查结果;所有患者均完成颈动脉和心脏彩超检查;采用白蛋白结合试验（albumin cobalt binding,ACB）测定患者IMA水平。采用Spearman相关分析IMA与其他指标的相关性;用二分类Logistic回归方法分析IMA与CVD的相关性。结果86例MHD患者IMA平均水平高于对照组[（95．24±18．06）kU／L比（56．58±12．36）kU／L,P〈0．05];CVD组患者IMA水平高于非CVD组患者[（115．27±16．38）kU／L比（81．64±19．82）kU／L,P〈0．013;IMA水平与低密度脂蛋白胆固醇（10wdensity lipoprotein cholesterol,LDL-C）、肌钙蛋白T（cardiactroponin T,cTnT）、超敏C反应蛋白（hinghsensitivityC-reactiveprotein,hs-CRP）、白细胞介素6（interleukin6,IL-6）、左室心肌重量指数（lef tventricular index,LVMI）、颈动脉内膜中层厚度（ca—rotidintima-mediathickness,IMT）呈正相关（r=0．402,P=0．036;r=0．584,P=0．021;r：0．514,P=0．023;r=0．396,P=0．042;r=0．610,P=0．002;r=0．537,P=0．022）,与Hb、Alb、左室射血分数（1eftventricular ejection fraction,LVEF）呈负相关（r=-0．387,P=0．026、r=-0．573,P〈0．01）1、r=-0．496,P=0．018）;二分类logistic回归分析显示,IMA、hs—CRP是MHD患者CVD的危险因素。结论MHD患者IMA水平显著升高,合并CVD患者升高更为明显,IMA是MHD患者CVD的独立危险因素,可以作为MHD患者CVD早期诊断标志物。     

维持性血液透析患者血浆同型半胱氨酸和血清脑钠肽检测的临床意义

目的：探讨维持性血液透析（maintenance hemodialysis,MHD）患者血浆同型半胱氨酸（homocysteine,Hcy）和血清脑钠肽（brain natriuretic peptide,BNP）水平与心血管疾病（cardiovascular disease,CVD）之间的关系。方法将95例 MHD患者分为心血管疾病组（CVD组）55例和无心血管疾病组（NCVD组）40例;另选30名健康对照者（健康对照组）,检测各组血浆 Hcy、血清BNP、血肌酐（SCr）、血糖（glucose,GLU）、血白蛋白（albumin,Alb）、血脂并进行比较。结果 MHD患者血浆 Hcy [（26.89＆#177;10.12）μmol/L]明显高于健康对照组[（8.05＆#177;2.53）μmol/L]（P〈0.01）;血清 BNP [（1275.02＆#177;1123.94）pg/ml]显著高于对照组[（57.82＆#177;34.61）pg/ml]（P〈0.01）;其中 CVD 组血浆 Hcy[（31.73＆#177;10.18）μmol/L]高于 NCVD 组[（20.24＆#177;5.01）μmol/L]（P〈0.01）;血清 BNP [（1957.49＆#177;1001.83）pg/ml]高于 NCVD组[（336.61＆#177;308.22）pg/ml]（P〈0.01）。以健康对照组血浆 Hcy 均数＋2倍标准差（x＋2s）（13.11μmol/L）为95%可信度上限,超过此值确定为高同型半胱氨酸血症（Hyperhomocysteinemia,HHcy）。95例 MHD患者 HHcy发生率为87.37%（83/95）;其中CVD组 HHcy占94.55%（52/55）,NCVD 组占77.50%（31/40）,均明显高于正常对照组6.67%（2/30）（均 P〈0.01）。CVD 组和 NCVD 组 SCr、GLU、Alb 及血脂比较,差异无统计学意义（P〉0.05）。CVD组血浆 Hcy与 SCr、Alb呈正相关（r=0.380、0.354,P〈0.01）,NCVD组血浆 HcyA与BNP、SCr、Alb呈正相关（r=0.341、0.337、0.389,P〈0.05）,血清 BNP 与 Hcy、SCr 呈正相关（r=0.341、0.389,P〈0.05）;血浆 Hcy、血清BNP与其余各血生化指标间无相关性（P〉0.05）。结论血浆 Hcy、血清BNP水平可作为 MHD患者CVD危险因素的预测指标。     

心肺转流下心血管手术孕妇死亡的危险因素分析

目的分析心肺转流(cardiopulmonary bypass,CPB)下心血管手术孕妇死亡的危险因素。方法回顾性分析我院35例孕妇行CPB下心血管手术的围术期资料,年龄22～37岁,将对孕妇死亡有明显影响的单因素纳入多因素Logistic回归分析。结果术后孕妇死亡5例,病死率为14.3%(5/35例)。单因素分析显示,术前NYHA心功能4级、手术时间、ICU留观时间、术后心力衰竭、术后透析对孕妇行CPB下心血管手术死亡有明显影响(P0.05)。多因素Logistic回归分析未能检测出孕妇行CPB下心血管手术死亡的独立危险因素。结论术前NYHA心功能4级、手术时间、ICU留观时间、术后心力衰竭、术后透析为孕妇行CPB下心血管手术死亡的危险因素。